According to the WS2812 data sheet, the device will operate from -25C. From what I have seen (in general terms, not with this LED in particular), the problem is worst at start up. Once going, the junction reaches an operating temperature above the ambient, and it is the upper temperature bound that limts the operational range. But I have a feeling that you knew that already!

@Photonscattering: Why exactly is this free advertising for adafruit? The "Neopixel" are just a rebranded, relatively common product called "WS2812" that can be bought for a fraction of the price from many other sources.

The thing about Adafruit is that your don't just sell you a box of WS2812s and then "run for the hills" -- they also provide a great library for the Arduino, plus useful example sketches that get yuou up-and-running really quickly -- and then they add do-it-yourself projects that you can either replicate or use a seed ideas for your own projects.

I'm not associated with Adafruit in any way -- except for the fact that I'm constantly buying stuff off them LOL

@Phononscattering - Why exactly is this free advertising for adafruit? The "Neopixel" are just a rebranded, relatively common product called "WS2812" that can be bought for a fraction of the price from many other sources.

It wasn't something I was aware of until you mentioned it so thanks for pointing that out.

Why exactly is this free advertising for adafruit? The "Neopixel" are just a rebranded, relatively common product called "WS2812" that can be bought for a fraction of the price from many other sources.